Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

A protocluster at z = 2.45

Journal Article · · Astrophysical Journal
;  [1];  [2]; ;  [3];  [4];  [5];  [6]
  1. Institute for Astronomy, Department of Physics, ETH Zurich, Zurich 8093 (Switzerland)
  2. European Southern Observatory, Alonso de Córdova 3107, Casilla 19001, Vitacura, Santiago (Chile)
  3. INAF, Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127, Bologna (Italy)
  4. Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782–0436 Macul, Santiago (Chile)
  5. Spitzer Science Center, 314–6 Caltech, Pasadena, CA 91125 (United States)
  6. Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France)

We present the spectroscopic confirmation of a z = 2.45 protocluster. Its member galaxies lie within a radius of 1.4 Mpc (physical) on the sky and within Δv±700 km s{sup −1} along the line of sight. We estimate an overdensity of 10, suggesting that the structure has made the turnaround but is not assembled yet. A comparison to the Millennium simulation suggests that analogous structures evolve into 10{sup 14}–10{sup 15} M{sub ⊙} h{sup −1} type dark matter halos by z = 0, qualifying the notion of “protocluster.” The search for the complete census of mock progenitor galaxies at z∼2.5 of these massive z = 0 mock clusters reveals that they are widely spread over areas with a diameter of 3–20 Mpc. This suggests that the optical selection of such protoclusters can result in a rich diversity regarding their z = 0 descendants. We also searched for signs of environmental differentiation in this protocluster. While we see a weak trend for more massive and more quiescent galaxies within the protocluster, this is not statistically significant.

OSTI ID:
22883305
Journal Information:
Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 802; ISSN ASJOAB; ISSN 0004-637X
Country of Publication:
United Kingdom
Language:
English

Similar Records

A first site of galaxy cluster formation: complete spectroscopy of a protocluster at z = 6.01
Journal Article · Mon Sep 01 00:00:00 EDT 2014 · Astrophysical Journal · OSTI ID:22365242

DISCOVERY OF A LARGE NUMBER OF CANDIDATE PROTOCLUSTERS TRACED BY ∼15 Mpc-SCALE GALAXY OVERDENSITIES IN COSMOS
Journal Article · Sun Feb 09 23:00:00 EST 2014 · Astrophysical Journal Letters · OSTI ID:22363998

Spectroscopic confirmation of a protocluster at z ≈ 3.786
Journal Article · Fri May 20 00:00:00 EDT 2016 · Astrophysical Journal · OSTI ID:22869077